In September 2016 (issue 143), Rail Engineer reported on the development and the proposed designs for the extensive remodelling and resignalling of Liverpool Lime Street station. At the time, the project had not obtained all the required funding and was still subject to gaining all the necessary approvals and consents. Rail Engineer is now pleased to report that all the planned work has indeed taken place, and that the challenges have all been overcome to deliver a successful project.
Collaboration with all stakeholders, including several train operators, the City of Liverpool and other organisations in the North West, was key to negotiating and securing the required disruptive access. It stimulated the production of a comprehensive and detailed transport strategy, with which the project staging strategy aligned. It also identified works required to manage passenger flow during key blockades.
The strategy called for Liverpool to be ‘kept open for business’ during stages 2 and 5 of the project, with trains terminating at Liverpool South Parkway. It was also the catalyst for a bi-directional signalling solution in order to retain some services into Lime Street while the significant reconstruction work continued.
Modelling
The need for the project was poor asset condition and the growing region – by 2043, the number of morning peak commuters is expected to double to more than 40,000 each day. Liverpool Lime Street is also a key part of the Northern Hub programme, which is a regulatory milestone for Network Rail.
The scheme has delivered a capacity increase of three extra services per hour by creating two new platforms while extending Platform 10 to accommodate eleven-car units and Platforms 1 and 2 for eight car units (previously four car). At the same time, Platforms 3 to 6 have been realigned to increase turnout speed and to provide safer, wider access for passengers.
All of the signalling has been renewed, with signalling control moved to the Manchester Rail Operating Centre (MROC). This equates to a 100 signalling equivalent unit (SEU) renewal, which is a sizeable scheme. Four kilometres of plain line track and 24 point ends have been renewed, along with the associated overhead line equipment.
Building Information Management (BIM), video simulation, and 4D modelling have all been used extensively as part of the planning and implementation process, which included ‘virtual route learning’ for Stage 5 to highlight safety risks to workers during the construction and for stakeholder management. BIM modelling was invaluable in interdisciplinary design reviews, identifying potential clashes on site and obtaining accurate measurements within the constricted Lime Street cutting to inform equipment siting and elevated cable route position.
The model was used extensively for signal sighting and identified the requirement for several sighting screens. This enabled the exact dimensions of the screens to be modelled for formal design and build, well in advance of the signals being installed and commissioned.
Hub and spoke
The project was delivered using a hub and spoke arrangement, in which organisations build a successful procurement strategy by integrating all the elements that are responsible for the delivery. The central hub facilitates communications and collaboration between the various spokes and manages the overall delivery strategy, providing sufficient process and assurance to enable effective working between spokes.
In this case, the ‘hub’ was led by Network Rail IP Signalling, which was responsible for signalling, operational telecoms, electrification and plant (E&P) and SCADA works, supported by Network Rail IP Northern Programmes (civil engineering and station works).
Buckingham Group Contracting planned and delivered all worksite management for the delivery of the project, including the eight blockades to deliver each key stage. This included all the civil engineering, platform works, plus station electrical, CCTV and customer information systems. Buckingham was supported by Motion Rail, which supplied the station information and security systems, while PICOW Engineering Group undertook the mechanical and electrical works.
A separate principal contractor organisation (also via Buckingham) coordinated the safe interface of all site works as well as delivering and managing the project site establishment and welfare facilities. S&C North Alliance delivered track and overhead line work, with design by Amey Consulting. Siemens Rail Automation delivered all of the signalling control, E&P, SCADA and operational telecommunications.
Acting as subcontractors to Buckingham, SNC-Lavalin’s Atkins business delivered the detailed design for the track, the majority of the civil engineering inclusive of all platform re-modelling and all station electrical and telecoms works. Atkins also addressed the track and platform interfaces, together with providing the formal BIM coordination role, while Arcadis provided a specialist role in the design of the civils and geotechnical interface for the OLE brackets required to support the new structures within the cutting and tunnels.
SPI, the creators of the virtual reality model, provided resources for 4D-modelling, model Integration within the hub team and produced the driver training video. Within Network Rail, the Signalling Design Group and Works Delivery organisations also delivered packages of work for the project, together with Babcock.
Starting position
The platform layout was, and is, somewhat confusing so it is worth taking a moment to clarify it.
Looking from the city centre entrance into the station, prior to the re-modelling, platforms were numbered from left to right and from 1 to 9. Platforms 1 to 6 were used predominantly for local services with Platforms 7 to 9 for longer distance services and longer trains.
The wide bay that contained Platforms 1 and 2 had an additional stabling siding – ‘A’ – running in between the two platform-facing tracks. Similarly, the bay for Platforms 3 and 4 included siding ‘B’.
There were originally two sidings between Platforms 5 and 6 – ‘C’ and ‘D’ – but siding C was removed in 1948. Platform 6 had quite a kink in it, which causes problems with signal sightings.
In the South Shed, what would logically be Platform 7 was, in fact, just siding ‘E’ – the support columns for the station roof, close to the platform edge, precluded it from being used for passengers. So Platform 7 was where one would expect to find Platform 8.
There was a wide space between Platform 7 and the last bay for Platforms 8 and 9. Formerly, this space was used for an access road, with a short bay platform at the top end protruding through a small bridge. This had also been removed, as had the bay on the far right that used to be Platforms 10 and 11. Since then, the space between platform faces 7 and 8 was used for waiting rooms and a redundant Post Office building.
Major changes
Platform 1 has been taken out of use, which has allowed the remaining platforms to be lengthened to allow for a minimum of six-car trains. The original Platform 6 has been straightened to improve signal sighting and reclassified as Platform 5.
The project removed waiting rooms, left luggage facilities and the redundant post office mail handling building between the existing Platforms 7 and 8 to create two new platform faces. The post office building removal itself was a major exercise due to redundant machinery and asbestos. Demolished by Buckingham’s own internal demolition team, the process required extensive excavation through sandstone rock together with infill of the former post office shaft tower and service tunnel. Some of the spoil was used to fill the voids, the remaining was removed from site by a combination of road and rail transport.
At the same time, the former Virgin Trains ticket office and waiting lounge buildings were carefully dismantled and placed in storage for future re-use.
The high level of ballast contamination in the Liverpool Lime Street station area, with asbestos and train discharge prominent in its make up, required safe removal and transportation to a waste facility. This was achieved successfully with no issues.
The new layout has provided five platforms on each side of the station, known as ‘North Shed’ and ‘South Shed’. Platform 10 (previously 9) has been extended from 246 to 267 metres. This is both to increase the number of platforms available for 11-car services from two to three and to increase the flexibility of train operations. Platforms 8, 9 and 10 have been resurfaced to match the newer paving in the North Shed, and all the platform coping edges have been changed to match the new track alignment.
The layout now allows trains using the slow lines to be predominantly routed to and from Platforms 1 to 5, while platforms 6 to 10 will serve the Fast lines. Departure speeds have been increased from 15 to 25 mph and the switches and crossings are now spaced further away from one another to enable independent tamping. The home signals are closer to the platforms ends and most platform-to-platform moves can be done under a main route, rather than as a shunt move.
New Mk3D fixed tension overhead line equipment (OLE) and new motorised operating switches have been provided to support the new track layout, but the proposal for motorised earthing switches for the OLE was removed from the scope of the scheme, as it was concluded the product was not sufficiently developed in time.
Signalling changes
The previous London, Midland & Scottish Railway Type 13 signalbox contained a 95-lever Westinghouse Brake & Signal Co Ltd Style ‘L’ miniature leaver frame, commissioned on 25 January 1948. It is being carefully removed and will be used to support the one remaining Style ‘L’ frame still operated by Network Rail, at Maidstone East. The signal box itself, located within the station throat and standing in a deep cutting, will be retained and may be reused for office space and storage.
New signalling equipment includes Frauscher wheel sensors, standard strength AWS (Automatic Warning System) magnets (permanent, electro and suppressed), TPWS (Train Protection and Warning System) transmitters, LED signals and indicators, miniature banners, and ‘right away’ and ‘train ready to start’ switches. All the points operating equipment is in-bearer Clamp Locks (IBCL) with condition monitoring.
The signalling is connected via the telecommunication FTNx Internet-protocol (IP) transmission network to a single workstation in the MROC. Traditionally, remote signalling was controlled via a telecom point to point link with a diverse routed back up link, possibly via another telecoms service provider, to provide continuity of service in the event of a failure. With an IP packet-based telecom network, however, the data messages are broken into individual packets of information and routed around a mesh network of routers and links. In the event of cable or equipment failure, multiple paths are available for the packets. Once all the packets are received, the data message is reassembled with any missing or corrupt packets resent. This all takes place in a few milliseconds.
‘Lime Street Control’ is a signalling control method in operation at a number of terminal stations. It uses the configuration of the train detection system to check that a platform has sufficient length before allowing the protecting signal to clear. As the name suggests, it was first provided at Liverpool, as part of the resignalling of the station in 1948.
During detailed design, a decision was made for Liverpool Lime Street to be controlled from a single dedicated workstation. An assessment of signaller workload confirmed that Automatic Route Setting (ARS) was not required. This meant that the Lime Street Control could not be provided as part of the ARS and, therefore, Lime Street Control has been provided in a conventional manner within the interlocking.
With LED signals, the access requirements for maintenance are significantly reduced and, due to the limited clearances in the Lime Street cutting, ladders and walkways to the new signal gantries have not been installed. Instead, a tower work-platform scaffold from LOBO Systems has been provided, which can quickly be installed should access be required.
To further improve safe maintenance access into the cutting, a new access point has been created at Crown Street, midpoint between Lime Street and Edge Hill. However, the planned trackside lockout device systems have not been provided, following a justification accepted by the Network Rail Safety Review Panel and the Office of Rail and Road (ORR). Lockout devices have been provided for all the platforms.
One innovation introduced by the project were combined alphanumeric route indicators (CARI) from Variable Message Signs (VMS), a Hill and Smith business. These can be used as a replacement for both standard alphanumeric route indicators (SARI), which have to have a readability of up to 250 metres, and miniature alphanumeric route indicators (MARI), which have a reduced readable distance of 65 metres. The new CARI indicators have been installed as ‘first of type’ at signals LL3067, LL5071 and LL9073 under a product acceptance trial certificate.
The re-control of the adjacent Edge Hill signal box to the Manchester ROC is now planned for 2019 and will be re-controlled onto the existing Liverpool (Huyton) workstation, leaving Lime Street with its own dedicated workstation.
Equipment locations
The project team was tasked with finding space with safe, easy and maintainable access for equipment to be located on the surface. Six multi-discipline equipment compounds were identified – five of these were on redundant bridges and areas of land above the cutting and were available for leaseback or purchase. The former bridge owners and tenants were, in general, pleased to help, so the inspection and maintenance of the structures, and the associated risk that may affect the operational railway, is now wholly in the control of the infrastructure manager. A sixth, multi-disciplinary equipment compound is situated on Liverpool Lime Street Platform 5.
Emergency spare cable ducts have been provided from the top of the cutting to track level. These are fitted with a draw rope to allow a failed cable to be replaced quickly and safely without the need for an isolation and disruptive track access for a work platform.
At St Andrews Street, an equipment compound has been located behind a new St Andrews ‘The Bullring’ mural, as part of a curved security wall around the compound. The original mural was unveiled by HRH Queen Elizabeth and Prince Phillip in July 1989 and commemorates the life and times of people who lived in nearby St Andrews Gardens, which opened in 1935 under a city housing programme.
In the same area, the project also undertook voluntary works within the local Bronte Youth Centre, investing almost £40,000 in improving the facilities there for local people.
The equipment within the compound itself consists of the signal relocatable equipment building (REB), 650V signalling power supply, point-heating control, telecoms transmission, SCADA (supervisory control and data acquisition) and junction lighting controls equipment.
Project stages
A comprehensive staging strategy gave stakeholders confidence in the successful delivery of the project and allowed the possession access requirements to be demonstrated, justified and agreed.
The new crossover ladder at Crown Street was installed early in the project but not commissioned until later. Likewise, switches and crossing units were installed at the entrance to the station to enable platform phasing in/out during the lead up to final commissioning. Bringing the points into service in stages allowed the significant platform alteration works to be carried out in a phased manner, which kept the overall blockade and station closure requirements to a minimum.
In October 2017, the bi-directional signalling system was installed and commissioned, which enabled trains to run in and out of Platforms 1 and 2 for much of the programme. For a number of smaller closures of Lime Street, and during the main blockades, long-distance trains terminated at Liverpool South Parkway with Merseyrail running additional services on the Northern Line to assist customers travelling to and from Liverpool.
Wall collapse
On Tuesday 28 February 2018, a section of the wall above the cutting collapsed, sending 200 tonnes of debris across four lines in the deep cutting approaching Lime Street station. The cause was not associated with the Lime Street project – the ground above the cutting had been overloaded, pushing the wall out and onto the railway – and fortunately no one was hurt. Other Network Rail teams worked 24/7 to clear a total of 4,000 tonnes of debris and to repair damage to the track, signalling and overhead wires. The line reopened on 8 March.
The incident did not affect the project and, in fact, the opportunity was taken to deliver some work that had been planned to take place later in the year. This included demolishment of many old buildings near the station and installing several undertrack crossings from one side of the station to the other.
The second major phase of the station’s transformation was an eight-week (2 June – 29 July 2018) blockade. This was known as stage 5, during which all station platforms were remodelled, lengthened and widened to create additional space for longer trains and more passengers. The bi-directional signalling for trains running in and out of Platforms 1 and 2 was recommissioned and used for almost five weeks of the blockade. Full train services resumed at Liverpool Lime Street on Monday 30 July.
The existing Platform 1 was abandoned; enabling the existing Platforms 2 and 3 to be extended. The existing sidings within the platforms were recovered to enable wider platforms to be achieved. A new Siemens Westlock interlocking was commissioned at MROC to control the Liverpool Lime Street area, with the control of signals and points via an IP-linked Westlock Trackside System (WTS).
During stage 5a, from 01:00 Saturday 2 June until 06:00 on Monday 11 June, Babcock, working for Siemens, installed temporary bidirectional signalling that would remain in service until the end of Stage 5b. Recovery of all trackside equipment was undertaken to facilitate track renewals. Siemens also worked within the Manchester ROC to relocate the Huyton workstation in order to facilitate the installation of the new Lime Street workstation.
Stage 5b (06:00 Monday 11 June – 20:00 Friday 13 July) delivered the reconnection of the signalling following the track works. Siemens undertook significant installation and local testing of all the new signalling equipment during this time.
Stage 5c 20:00 Friday 13 July – 04:45 Monday 30 July was the fringe changeover stage with principles and wheels-free testing as all track works were now complete. Siemens carried out changeovers within Edge Hill relay room, including a power re-feed from a new supply point. Additional works to the Edge Hill signalling panel were also undertaken so as to reflect the Lime Street changes and fringe to the Manchester ROC.
In total, stage 5 delivered:
- The new workstation at the ROC;
- One Westlock Interlocking;
- One power supply point
- Three combined alphanumeric route indicator signals (on);
- Six REBs containing new-technology Westlock Trackside System (WTS);
- 16 AWS magnets;
- 24 point ends;
- 38 TPWS transmitters;
- 84 Frauscher axle-counter heads;
- 85 new/altered signals (including 14 lightweight signals, eight on gantry, 10 off right away, nine miniature banner, nine ground position light signals);
- More than 120 signalling available routes;
- Over 135km of miscellaneous cable.
Some additional, final works took place on Sunday 2 September and Sunday 14 October with the new Platforms 1 and 2 in full passenger use. This now allows for the extra three services per hour in and out of Lime Street station, including new direct services to Scotland.
The rail industry sometimes has a poor reputation for delivering major projects, but the Lime Street remodelling was a complicated and significant project with many interfaces and risks. It has, however, been successfully delivered and has provided the opportunity to provide a much better layout to suit todays railway, and one that is maintainable, sustainable and is able to support the Northern Power House.
Thanks to Ian Fury and Claire Hulstone of Network Rail, Fergal Kiernan of Buckingham Group Contracting and James Davies of Siemens for their help with this article.
